Carisma Therapeutics (CARM) 10-Q 8 Aug 24 2024 Q2 Quarterly report Financial data

Cover

Cover - shares	6 Months Ended
	Jun. 30, 2024	Aug. 06, 2024
Cover [Abstract]
Document Type	10-Q
Document Quarterly Report	true
Document Period End Date	Jun. 30, 2024
Document Transition Report	false
Entity File Number	001-36296
Entity Registrant Name	Carisma Therapeutics Inc.
Entity Incorporation, State or Country Code	DE
Entity Tax Identification Number	26-2025616
Entity Address, Address Line One	3675 Market Street
Entity Address, Address Line Two	Suite 401
Entity Address, City or Town	Philadelphia
Entity Address, State or Province	PA
Entity Address, Postal Zip Code	19104
City Area Code	267
Local Phone Number	491-6422
Title of 12(b) Security	Common Stock, $0.001 par value per share
Trading Symbol	CARM
Security Exchange Name	NASDAQ
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Non-accelerated Filer
Entity Small Business	true
Entity Emerging Growth Company	false
Entity Shell Company	false
Entity Common Stock, Shares Outstanding		41,544,975
Entity Central Index Key	0001485003
Current Fiscal Year End Date	--12-31
Amendment Flag	false
Document Fiscal Year Focus	2024
Document Fiscal Period Focus	Q2

Unaudited Consolidated Balance

Unaudited Consolidated Balance Sheets - USD ($) $ in Thousands	Jun. 30, 2024	Dec. 31, 2023
Current assets:
Cash and cash equivalents	$ 40,362	$ 77,605
Prepaid expenses and other assets	10,359	2,866
Total current assets	50,721	80,471
Property and equipment, net	6,531	6,764
Right of use assets – operating leases	1,945	2,173
Deferred financing costs	142	146
Total assets	59,339	89,554
Current liabilities:
Accounts payable	2,033	3,933
Accrued expenses	9,241	7,662
Deferred revenue	659	1,413
Operating lease liabilities	1,179	1,391
Finance lease liabilities	1,283	544
Other current liabilities	1,222	965
Total current liabilities	15,617	15,908
Deferred revenue	41,250	45,000
Operating lease liabilities	795	860
Finance lease liabilities	502	328
Other long-term liabilities	815	926
Total liabilities	58,979	63,022
Commitments and contingencies (Note 6)
Stockholders’ equity:
Preferred stock $0.001 par value, 5,000,000 shares authorized, none issued or outstanding	0	0
Common stock $0.001 par value, 350,000,000 shares authorized, 41,544,975 and 40,609,915 shares issued and outstanding at June 30, 2024 and December 31, 2023, respectively	41	40
Additional paid-in capital	275,561	271,594
Accumulated deficit	(275,242)	(245,102)
Total stockholders’ equity	360	26,532
Total liabilities and stockholders’ equity	$ 59,339	$ 89,554

Unaudited Consolidated Balanc_2

Unaudited Consolidated Balance Sheets (Parenthetical) - $ / shares	Jun. 30, 2024	Dec. 31, 2023
Statement of Financial Position [Abstract]
Preferred stock, par value (in USD per share)	$ 0.001	$ 0.001
Preferred stock, shares authorized (in shares)	5,000,000	5,000,000
Preferred stock, shares issued (in shares)	0	0
Preferred stock, shares outstanding (in shares)	0	0
Common stock, par value (in USD per share)	$ 0.001	$ 0.001
Common stock, shares authorized (in shares)	350,000,000	350,000,000
Common stock, shares issued (in shares)	41,544,975	40,609,915
Common stock, shares outstanding (in shares)	41,544,975	40,609,915

Unaudited Consolidated Statemen

Unaudited Consolidated Statements of Operations and Comprehensive Loss - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2024	Jun. 30, 2023	Jun. 30, 2024	Jun. 30, 2023
Statement of Comprehensive Income [Abstract]
Collaboration revenues	$ 9,197	$ 3,560	$ 12,594	$ 6,803
Operating expenses:
Research and development	15,307	18,518	32,769	35,159
General and administrative	5,560	6,007	11,005	15,581
Total operating expenses	20,867	24,525	43,774	50,740
Operating loss	(11,670)	(20,965)	(31,180)	(43,937)
Change in fair value of derivative liability	0	0	0	(84)
Interest income (expense), net	508	1,177	1,040	(300)
Pre-tax loss	(11,162)	(19,788)	(30,140)	(44,321)
Income tax expense	0	(88)	0	(197)
Net loss	$ (11,162)	$ (19,876)	$ (30,140)	$ (44,518)
Share information:
Net loss per share of common stock, basic (in USD per share)	$ (0.27)	$ (0.49)	$ (0.73)	$ (1.67)
Net loss per share of common stock, diluted (in USD per share)	$ (0.27)	$ (0.49)	$ (0.73)	$ (1.67)
Weighted-average shares of common stock outstanding, basic (in shares)	41,543,553	40,258,107	41,241,009	26,596,712
Weighted-average shares of common stock outstanding, diluted (in shares)	41,543,553	40,258,107	41,241,009	26,596,712
Comprehensive loss
Net loss	$ (11,162)	$ (19,876)	$ (30,140)	$ (44,518)
Unrealized gain on marketable securities	0	129	0	306
Comprehensive loss	$ (11,162)	$ (19,747)	$ (30,140)	$ (44,212)

Unaudited Consolidated Statem_2

Unaudited Consolidated Statements of Convertible Preferred Stock and Stockholders' Equity (Deficit) - USD ($) $ in Thousands	Total	Common stock	Additional paid-in capital	Accumulated other comprehensive (loss) income	Accumulated deficit	Noncontrolling interests
Beginning balance (in shares) at Dec. 31, 2022	8,700,885
Beginning balance at Dec. 31, 2022	$ 107,808
Convertible preferred stock
Conversion of convertible preferred stock and non-controlling interests to common stock (in shares)	(8,700,885)
Conversion of convertible preferred stock and non-controlling interests to common stock	$ (107,808)
Ending balance (in shares) at Mar. 31, 2023	0
Ending balance at Mar. 31, 2023	$ 0
Beginning balance (in shares) at Dec. 31, 2022		2,217,737
Beginning balance at Dec. 31, 2022	(142,670)	$ 2	$ 1,197	$ (41)	$ (158,223)	$ 14,395
Stockholders' Equity (Deficit)
Stock-based compensation	265	$ 0	265
Unrealized gain on marketable securities	177			177
Issuance of common stock for cash in pre-closing financing (in shares)		3,730,608
Issuance of common stock for cash in pre-closing financing	30,640	$ 4	30,636
Issuance of common stock upon settlement of convertible promissory note, accrued interest, and related derivative liability (in shares)		5,059,338
Issuance of common stock upon settlement of convertible promissory note, accrued interest, and related derivative liability	42,447	$ 5	42,442
Issuance of common stock to Sesen Bio shareholders in reverse capitalization (in shares)		10,374,272
Issuance of common stock to Sesen Bio shareholders in reverse capitalization	72,044	$ 10	72,034
Conversion of convertible preferred stock and non-controlling interests to common stock (in shares)		18,872,711
Conversion of convertible preferred stock and non-controlling interests to common stock	107,809	$ 19	122,185			(14,395)
Net loss	(24,642)				(24,642)
Ending balance (in shares) at Mar. 31, 2023		40,254,666
Ending balance at Mar. 31, 2023	$ 86,070	$ 40	268,759	136	(182,865)	0
Beginning balance (in shares) at Dec. 31, 2022	8,700,885
Beginning balance at Dec. 31, 2022	$ 107,808
Ending balance (in shares) at Jun. 30, 2023	0
Ending balance at Jun. 30, 2023	$ 0
Beginning balance (in shares) at Dec. 31, 2022		2,217,737
Beginning balance at Dec. 31, 2022	(142,670)	$ 2	1,197	(41)	(158,223)	14,395
Stockholders' Equity (Deficit)
Unrealized gain on marketable securities	306
Net loss	(44,518)
Ending balance (in shares) at Jun. 30, 2023		40,269,576
Ending balance at Jun. 30, 2023	$ 66,705	$ 40	269,141	265	(202,741)	0
Beginning balance (in shares) at Mar. 31, 2023	0
Beginning balance at Mar. 31, 2023	$ 0
Ending balance (in shares) at Jun. 30, 2023	0
Ending balance at Jun. 30, 2023	$ 0
Beginning balance (in shares) at Mar. 31, 2023		40,254,666
Beginning balance at Mar. 31, 2023	86,070	$ 40	268,759	136	(182,865)	0
Stockholders' Equity (Deficit)
Exercise of stock options (in shares)		14,910
Exercise of stock options	52		52
Stock-based compensation	330	$ 0	330
Unrealized gain on marketable securities	129			129
Net loss	(19,876)				(19,876)
Ending balance (in shares) at Jun. 30, 2023		40,269,576
Ending balance at Jun. 30, 2023	$ 66,705	$ 40	269,141	265	(202,741)	0
Beginning balance (in shares) at Dec. 31, 2023	0
Beginning balance at Dec. 31, 2023	$ 0
Ending balance (in shares) at Mar. 31, 2024	0
Ending balance at Mar. 31, 2024	$ 0
Beginning balance (in shares) at Dec. 31, 2023		40,609,915
Beginning balance at Dec. 31, 2023	26,532	$ 40	271,594	0	(245,102)	0
Stockholders' Equity (Deficit)
Exercise of stock options (in shares)		1,579
Exercise of stock options	2		2
Stock-based compensation	1,057	$ 0	1,057
Sale of common stock under Open Market Sales Agreement, net of issuance costs (in shares)		931,250
Sale of common stock under Open Market Sales Agreement, net of issuance costs	2,282	$ 1	2,281
Net loss	(18,978)				(18,978)
Ending balance (in shares) at Mar. 31, 2024		41,542,744
Ending balance at Mar. 31, 2024	$ 10,895	$ 41	274,934	0	(264,080)	0
Beginning balance (in shares) at Dec. 31, 2023	0
Beginning balance at Dec. 31, 2023	$ 0
Ending balance (in shares) at Jun. 30, 2024	0
Ending balance at Jun. 30, 2024	$ 0
Beginning balance (in shares) at Dec. 31, 2023		40,609,915
Beginning balance at Dec. 31, 2023	$ 26,532	$ 40	271,594	0	(245,102)	0
Stockholders' Equity (Deficit)
Exercise of stock options (in shares)	3,810
Unrealized gain on marketable securities	$ 0
Net loss	(30,140)
Ending balance (in shares) at Jun. 30, 2024		41,544,975
Ending balance at Jun. 30, 2024	$ 360	$ 41	275,561	0	(275,242)	0
Beginning balance (in shares) at Mar. 31, 2024	0
Beginning balance at Mar. 31, 2024	$ 0
Ending balance (in shares) at Jun. 30, 2024	0
Ending balance at Jun. 30, 2024	$ 0
Beginning balance (in shares) at Mar. 31, 2024		41,542,744
Beginning balance at Mar. 31, 2024	10,895	$ 41	274,934	0	(264,080)	0
Stockholders' Equity (Deficit)
Exercise of stock options (in shares)		2,231
Exercise of stock options	2		2
Stock-based compensation	625	$ 0	625
Unrealized gain on marketable securities	0
Net loss	(11,162)				(11,162)
Ending balance (in shares) at Jun. 30, 2024		41,544,975
Ending balance at Jun. 30, 2024	$ 360	$ 41	$ 275,561	$ 0	$ (275,242)	$ 0

Unaudited Consolidated Statem_3

Unaudited Consolidated Statement of Cash Flows - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2024	Jun. 30, 2023
Cash flows from operating activities:
Net loss	$ (30,140)	$ (44,518)
Adjustment to reconcile net loss to net cash used in operating activities:
Depreciation and amortization expense	1,948	1,420
Stock-based compensation expense	1,682	595
Reduction in the operating right of use assets	4,565	2,683
Amortization of debt discount	0	1,283
Change in fair value of derivative liability	0	84
Accretion on marketable securities	0	(569)
Write-off of property and equipment	67	0
Non-cash interest expense	159	68
Changes in operating assets and liabilities:
Prepaid expenses and other assets	(7,493)	(1,210)
Accounts payable	(1,900)	659
Accrued expenses	1,580	(1,618)
Deferred revenue	(4,504)	(1,043)
Operating lease liabilities	(4,614)	(1,915)
Other liabilities	105	0
Net cash used in operating activities	(38,545)	(44,081)
Cash flows from investing activities:
Purchase of marketable securities	0	(34,460)
Proceeds from the sale of marketable securities	0	67,000
Purchases of property and equipment	(123)	(382)
Net cash (used in) provided by investing activities	(123)	32,158
Cash flows from financing activities:
Cash, cash equivalents and restricted cash acquired in connection with the reverse recapitalization	0	37,903
Payment of reverse recapitalization finance costs	0	(5,202)
Proceeds from the issuance of common stock in pre-closing financing	0	30,640
Payment of principal related to finance lease liabilities	(906)	(213)
Proceeds from failed sale-leaseback arrangement	686	1,020
Payment of finance liability from failed sale-leaseback arrangement	(645)	(88)
Proceeds from the exercise of stock options	4	52
Sale of common stock under Open Market Sales Agreement	2,286	0
Net cash provided by financing activities	1,425	64,112
Net (decrease) increase in cash, cash equivalents and restricted cash	(37,243)	52,189
Cash, cash equivalents and restricted cash at beginning of the period	77,605	24,194
Cash, cash equivalents and restricted cash at end of the period	40,362	76,383
Supplemental disclosures of cash flow information:
Cash paid for interest	105	88
Supplemental disclosure of non-cash financing and investing activities:
Conversion of convertible preferred stock and non-controlling interests upon Merger	0	122,204
Conversion of convertible promissory note, accrued interest and derivative liability upon Merger	0	42,447
Reverse recapitalization costs in accrued expenses	0	611
Unrealized gain on marketable securities	0	306
Deferred financing costs in accounts payable	0	86
Deferred financing costs in accrued expenses	0	60
Reclassification of deferred financing costs to additional paid-in capital	4	0
Right-of-use assets obtained in exchange for new operating lease liabilities	4,337	908
Right-of-use assets obtained in exchange for new financing lease liabilities	$ 1,660	$ 0

Background

Background	6 Months Ended
	Jun. 30, 2024
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Background	Background Carisma Therapeutics Inc., a Delaware corporation (collectively with its subsidiaries, the Company), is a clinical-stage cell therapy company focused on using the Company’s proprietary cell therapy platform to develop transformative immunotherapies to treat cancer and other serious diseases. The Company has created this comprehensive cell therapy platform to enable the therapeutic use of engineered macrophages and monocytes, which belong to a subgroup of white blood cells called myeloid cells. The Company’s focus is its proprietary chimeric antigen receptor macrophage and monocyte (CAR-M) cell therapy platform, which redirects macrophages against specific tumor associated antigens and enables targeted anti-tumor immunity by utilizing genetically modified myeloid cells (macrophages and monocytes) to express chimeric antigen receptors (CARs), enabling these potent innate immune cells to recognize specific tumor associated antigens on the surface of tumor cells. The Company has an ex vivo oncology program and an in vivo oncology program. In addition, the Company utilizes its cell therapy platform to engineer macrophages with the potential to treat fibrosis. Ex Vivo Oncology Program — The Company's lead product candidate, CT-0525, is intended to treat solid tumors that over-express human epidermal growth factor receptor 2 (HER2), a protein found on the surface of a variety of solid tumors, including breast cancer, gastric cancer, esophageal cancer, salivary gland cancer, and others. CT-0525 utilizes a novel approach to CAR-M therapy that engineers patients’ monocytes directly, without ex vivo differentiation into macrophages. The Company believes that engineering monocytes directly (CAR-Monocyte) will result in a therapy with favorable attributes compared to engineering after ex vivo differentiation (CAR-Macrophage) and that this approach has the potential to improve upon the anti-tumor effect seen with CAR-Macrophages. In Vivo Oncology Program (Moderna Collaboration) — In addition to the Company's clinical program in ex vivo cell therapy, the Company has an in vivo mRNA/lipid nanoparticle (LNP) CAR-M program in partnership with ModernaTX Inc. (Moderna). This collaboration utilizes Moderna's mRNA/LNP technology, together with the Company's CAR-M platform technology, to create novel in vivo oncology off the shelf gene therapy products. Fibrosis Program — Using its macrophage and monocyte engineering platform, the Company is also pursuing early research and development of multiple assets for the potential treatment of diseases beyond oncology, including fibrosis and other immunologic and inflammatory diseases. In the second quarter of 2024, the Company achieved preclinical proof of concept in its liver fibrosis program, demonstrating the anti-fibrotic potential of engineered macrophages in two liver fibrosis models. The Company's first product candidate to enter clinical development, CT-0508, was the first CAR-Macrophage to be evaluated in a human clinical trial and was an anti-HER2 product candidate. The Company also enrolled six patients in a sub-study evaluating the co-administration of CT-0508 and pembrolizumab, a programmed cell death protein 1 checkpoint inhibitor, evaluating the safety and tolerability of the co-administration, along with several customary secondary endpoints.

Development-Stage Risks and Liq

Development-Stage Risks and Liquidity	6 Months Ended
	Jun. 30, 2024
Development-Stage Risks and Liquidity
Development-Stage Risks and Liquidity	Development-Stage Risks and Liquidity The Company has incurred losses and negative cash flows from operations since inception and has an accumulated deficit of $275.2 million as of June 30, 2024. The Company anticipates incurring additional losses until such time, if ever, that it can generate significant sales from its product candidates currently in development. Management expects its cash and cash equivalents of $40.4 million as of June 30, 2024 and $2.0 million received in July 2024 under the Moderna Collaboration and License Agreement are sufficient to sustain planned operations into, but not through, the third quarter of 2025. As a result, the Company has concluded that there is substantial doubt about its ability to continue as a going concern within one year after the date that the consolidated financial statements are issued. The Company's cash forecast contains estimates and assumptions, and management cannot predict the timing of all cash receipts and expenditures with certainty. Variances from management's estimates and assumptions could impact the Company's liquidity prior to the third quarter of 2025. The accompanying unaudited interim consolidated financial statements have been prepared on a going-concern basis, which contemplates the realization of assets and satisfaction of liabilities in the normal course of business. The unaudited interim consolidated financial statements do not include any adjustments related to the recoverability and classification of recorded asset amounts or the amounts and classification of liability that might result from the outcome of this uncertainty. Management is currently evaluating different strategies to obtain the required funding for future operations. These strategies may include, but are not limited to, private placements of equity and/or debt, other offerings of equity and/or debt securities, licensing arrangements and/or marketing arrangements. There is no assurance that such financing will be available when needed. The Company also intends to continue to re-assess its expense allocation. The Company is subject to those risks associated with any specialty biotechnology company that has substantial expenditures for research and development. There can be no assurance that the Company’s research and development projects will be successful, that products developed will obtain necessary regulatory approval, or that any approved product will be commercially viable. In addition, the Company operates in an environment of rapid technological change and is largely dependent on the services of its employees and consultants.

Summary of Significant Accounti

Summary of Significant Accounting Policies	6 Months Ended
	Jun. 30, 2024
Accounting Policies [Abstract]
Summary of Significant Accounting Policies	Summary of Significant Accounting Policies Interim Financial Statements The summary of significant accounting policies is included in the Company’s audited consolidated financial statements and related notes as of and for the year ended December 31, 2023 found in the Annual Report filed on Form 10-K filed with the Securities and Exchange Commission (SEC) on April 1, 2024. The accompanying unaudited interim consolidated financial statements have been prepared in accordance with U.S. generally accepted accounting principles (GAAP). Any references in these notes to applicable guidance is meant to refer to GAAP as found in Accounting Standards Codification (ASC) and Accounting Standards Update (ASU) promulgated by the Financial Accounting Standards Board (FASB). The accompanying unaudited interim consolidated financial statements include the accounts of the Company and its wholly owned subsidiaries. In the opinion of management, the accompanying unaudited interim consolidated financial statements include all normal and recurring adjustments (which consist primarily of accruals, estimates and assumptions that impact the unaudited interim consolidated financial statements) considered necessary to present fairly the Company’s financial position as of June 30, 2024 and its results of operations for the three and six months ended June 30, 2024 and 2023. Operating results for the three and six months ended June 30, 2024 are not necessarily indicative of the results that may be expected for the year ending December 31, 2024. The unaudited interim consolidated financial statements, presented herein, do not contain all of the required disclosures under GAAP for annual financial statements. The accompanying unaudited interim consolidated financial statements should be read in conjunction with the audited consolidated financial statements and related notes as of and for the year ended December 31, 2023 found in the Annual Report filed on Form 10-K filed with the SEC on April 1, 2024. Use of Estimates The preparation of unaudited interim consolidated financial statements in conformity with GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at the date of the unaudited interim consolidated financial statements and the reported amounts of revenues and expenses during the reporting period. Actual results could differ from such estimates. Estimates and assumptions are periodically reviewed, and the effects of revisions are reflected in the unaudited interim consolidated financial statements in the period they are determined to be necessary. Significant areas that require management’s estimates include accrued research and development expenses. Fair Value of Financial Instruments Management believes that the carrying amounts of the Company’s financial instruments, including cash equivalents and accounts payable, approximate fair value due to the short-term nature of those instruments. Fair Value Measurements The Company utilizes valuation techniques that maximize the use of observable inputs and minimize the use of unobservable inputs to the extent possible. The Company determines fair value based on assumptions that market participants would use in pricing an asset or liability in the principal or most advantageous market. When considering market participant assumptions in fair value measurements, the following fair value hierarchy distinguishes between observable and unobservable inputs, which are categorized in one of the following levels: • Level 1 Inputs: Unadjusted quoted prices in active markets for identical assets or liabilities accessible to the reporting entity at the measurement date. • Level 2 Inputs: Other than quoted prices included in Level 1 inputs that are observable for the asset or liability, either directly or indirectly, for substantially the full term of the asset or liability. • Level 3 Inputs: Unobservable inputs for the asset or liability used to measure fair value to the extent that observable inputs are not available, thereby allowing for situations in which there is little, if any, market activity for the asset or liability at the measurement date. The following fair value hierarchy table presents information about the Company’s assets and liabilities measured at fair value on a recurring basis: (in thousands) Fair value measurement at reporting date using (Level 1) (Level 2) (Level 3) June 30, 2024 Assets: Cash equivalents – money markets accounts $ 37,288 $ — $ — December 31, 2023 Assets: Cash equivalents – money markets accounts $ 62,999 $ — $ — During the six months ended June 30, 2024 and 2023, there were no transfers between Level 1, Level 2 and Level 3. Concentration of credit risk Financial instruments that potentially subject the Company to significant concentrations of credit risk consist primarily of cash and cash equivalents. The Company maintains deposits in federally insured financial institutions in excess of federally insured limits. The Company has not experienced any losses in such accounts and believes it is not exposed to significant risk on its cash and cash equivalents. Segment information Operating segments are defined as components of an enterprise about which separate discrete information is available for evaluation by the chief operating decision maker, or decision-making group, in deciding how to allocate resources and in assessing performance. The Company views its operations and manages its business in one segment. Net loss per share Basic net loss per share of common stock is computed by dividing net loss by the weighted-average number of shares of common stock outstanding during each period. Diluted net loss per share of common stock includes the effect, if any, from the potential exercise or conversion of securities, such as convertible preferred stock and stock options, which would result in the issuance of incremental shares of common stock. For diluted net loss per share, the weighted-average number of shares of common stock is the same for basic net loss per share due to the fact that when a net loss exists, potentially dilutive securities are not included in the calculation as their impact is anti-dilutive. The following potentially dilutive securities have been excluded from the computation of diluted weighted-average shares of common stock outstanding, as they would be anti-dilutive: June 30, 2024 2023 Stock options 8,685,238 6,655,749 Recently issued accounting pronouncements In November 2023, the FASB issued ASU 2023-07, Segment Reporting (Topic 280): Improvements to Reportable Segment Disclosures (ASU 2023-07), which requires disclosure of incremental segment information on an annual and interim basis. This ASU is effective for fiscal years beginning after December 15, 2023, and interim periods within fiscal years beginning after December 15, 2024 on a retrospective basis. The Company is currently evaluating the effect of this pronouncement on its disclosures. In December 2023, the FASB issued ASU 2023-09, Income Taxes (Topic 740): Improvements to Income Tax Disclosures (ASU 2023-09), which expands the disclosures required for income taxes. This ASU is effective for fiscal years beginning after December 15, 2024, with early adoption permitted. The amendment should be applied on a prospective basis while retrospective application is permitted. The Company is currently evaluating the effect of this pronouncement on its disclosures.

Prepaid Expenses and other asse

Prepaid Expenses and other assets	6 Months Ended
	Jun. 30, 2024
Deferred Costs, Capitalized, Prepaid, and Other Assets Disclosure [Abstract]
Prepaid Expenses and other assets	Prepaid Expenses and other assets Prepaid expenses and other assets consisted of the following (in thousands): June 30, 2024 December 31, 2023 Research and development $ 1,279 $ 278 Novartis credit (Note 6) 4,000 — Collaboration Receivable (Note 10) 2,000 — Deposits 1,548 891 Insurance 725 402 Other 807 1,295 $ 10,359 $ 2,866

Accrued Expenses

Accrued Expenses	6 Months Ended
	Jun. 30, 2024
Payables and Accruals [Abstract]
Accrued Expenses	Accrued Expenses Accrued expenses consisted of the following (in thousands): June 30, 2024 December 31, 2023 Research and development $ 2,803 $ 3,131 Professional fees 414 1,366 Compensation and related expenses 1,562 3,100 Novartis termination fee (Note 6) 4,409 — Other 53 65 $ 9,241 $ 7,662

Commitments and Contingencies

Commitments and Contingencies	6 Months Ended
	Jun. 30, 2024
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies	Commitments and Contingencies Leases The Company has operating leases for its laboratory and office space in Philadelphia, Pennsylvania. The Company’s operating leases have term end dates ranging from 2024 to 2029. The Company also has obligations under an arrangement for the use of certain laboratory equipment that are classified as finance leases that commenced in 2022 and have end dates ranging from 2024 to 2026. Effective February 2024, the Company renewed an existing operating lease with an end date through 2026. In April 2024, in connection with the revised operating plan, the Company notified the lessor that it would terminate the lease effective August 2024. In July 2024, the Company entered into an amendment extending the termination of the lease to June 2025 with an option to extend to December 2025. The Company’s operating and finance lease right-of-use (ROU) assets and the related lease liabilities are initially measured at the present value of future lease payments over the lease term. The Company is responsible for payment of certain real estate taxes, insurance and other expenses on certain of its leases. These amounts are generally considered to be variable and are not included in the measurement of the ROU assets and lease liability. The Company accounts for non-lease components, such as maintenance, separately from lease components. The Company carries laboratory equipment from failed sale leasebacks, as property and equipment, net on the accompanying unaudited interim consolidated balance sheets. The ongoing lease payments are recorded as reductions to the finance liability and interest expense. As of June 30, 2024, the Company had a $2.0 million financing liability recorded in other current liabilities and other long-term liabilities on the unaudited interim consolidated balance sheets. The elements of the lease costs were as follows (in thousands): Six Months Ended June 30, 2024 2023 Operating lease cost $ 3,154 $ 2,875 Finance lease cost: Amortization of lease assets 1,008 593 Interest on lease liabilities 159 88 Total finance lease cost 1,167 681 Variable lease cost 672 653 Total lease cost $ 4,993 $ 4,209 Lease term and discount rate information related to leases was as follows: June 30, 2024 2023 Weighted-average remaining lease term (in years) Operating leases 2.5 2.2 Finance leases 1.4 1.7 Weighted-average discount rate Operating leases 9.8 % 9.6 % Finance leases 9.0 % 9.0 % Supplemental cash flow information was as follows (in thousands): Six Months Ended 2024 2023 Cash paid for amounts included in the measurement of lease liabilities: Operating cash used in operating leases $ 3,203 $ 2,584 Operating cash used in finance leases $ 159 $ 88 Financing cash used in finance leases $ 906 $ 213 Future maturities of lease liabilities were as follows as of June 30, 2024 (in thousands): Operating Finance Fiscal year ending: 2024 (remaining six months) $ 1,177 $ 631 2025 219 1,261 2026 226 20 2027 233 — 2028 240 — Thereafter 184 — Total future minimum payments 2,279 1,912 Less imputed interest (305) (127) Present value of lease liabilities $ 1,974 $ 1,785 Manufacturing and Supply Agreement In March 2023, the Company entered into a manufacturing and supply agreement (Novartis Agreement) with Novartis Pharmaceuticals Corporation (Novartis) for the manufacturing of the Company’s CT-0508 product candidate. The Novartis Agreement is for five years and shall renew automatically for additional one-year periods unless and until terminated by either party. In addition to paying to manufacture the product, the Company will also pay $1.0 million per calendar year, payable in quarterly payments, for reserved capacity starting on the date on which the Novartis site is declared ready to produce CT-0508 as determined by the Company. In the event of termination without cause by the Company, a termination fee equal to $4.0 million will be payable by Carisma to Novartis which, pursuant to the terms of the agreement, can be credited in full against amounts due for a substitute product. On June 26, 2024, in furtherance of its revised operating plan, the Company terminated the Novartis Agreement. Upon termination, the Company incurred a termination fee equal to $4.0 million and recorded a $4.0 million accrued expense and corresponding prepaid asset within the accompanying unaudited consolidated balance sheet. A prepaid asset was recorded as the Company has separately agreed with Novartis that if Novartis and the Company enter into an agreement for the tech transfer of another product to Novartis on or before December 31, 2024, then the $4.0 million termination fee shall be credited in full or in part against any amounts due from the Company to Novartis under such agreement relating to the substitute product. The Company and Novartis intend to negotiate a similar agreement with respect to CT-0525 in the fall of 2024. Contingencies Liabilities for loss contingencies, arising from claims, assessments, litigation, fines, penalties, and other sources are recorded when it is probable that a liability has been incurred and the amount of the assessment and/or remediation can be reasonably estimated. No such loss contingencies were probable nor reasonably estimable as of June 30, 2024.

Stockholders' Equity

Stockholders' Equity	6 Months Ended
	Jun. 30, 2024
Stockholders' Equity Note [Abstract]
Stockholders' Equity	Stockholders’ Equity Open Market Sales Agreement On May 12, 2023, the Company entered into an Amended and Restated Open Market Sale Agreement SM with Jefferies LLC, as sales agent, pursuant to which the Company may offer and sell shares of its common stock with an aggregate offering price of up to $100.0 million under an “at-the-market" offering program. During the six months ended June 30, 2024, the Company sold 931,250 shares and received net proceeds of $2.3 million in connection with the Company's "at-the-market" offering program.

Stock-based Compensation

Stock-based Compensation	6 Months Ended
	Jun. 30, 2024
Share-Based Payment Arrangement [Abstract]
Stock-based Compensation	Stock-based Compensation 2017 Stock Incentive Plan The Company adopted the CARISMA Therapeutics Inc. 2017 Stock Incentive Plan, as amended (the Legacy Carisma Plan), that provided for the grant of incentive stock options to employees, directors, and consultants. The maximum term of options granted under the Legacy Carisma Plan was ten years, and stock options typically vested over a four-year period. The Company’s stock options vest based on the terms in the awards agreements and generally vest over four years. Upon completion of the Merger, the Company assumed the Legacy Carisma Plan and the outstanding and unexercised options issued thereunder, and ceased granting awards under the Legacy Carisma Plan. 2014 Stock Incentive Plan Stock options outstanding under the 2014 Amended and Restated Stock Incentive Plan (the 2014 Plan) generally vest over a four-year period and are exercisable for a period of ten years from the date of grant. As of June 30, 2024, approximately 3.8 million shares of common stock remained available for issuance. 2014 Employee Stock Purchase Plan The Carisma Therapeutics Inc. 2014 Employee Stock Purchase Plan had 0.2 million shares of common stock available for issuance as of June 30, 2024. The following table summarizes stock option activity for the six months ended June 30, 2024: Options Weighted Weighted Aggregate Outstanding as of December 31, 2023 6,023,370 $ 3.94 Exercised (3,810) 0.99 $ 4 Granted 3,674,365 1.77 Forfeited (1,008,687) 4.70 Outstanding as of June 30, 2024 8,685,238 $ 2.93 8.14 $ 2,018 Exercisable as of June 30, 2024 3,487,670 $ 2.19 6.40 $ 1,517 The weighted-average grant-date per share fair values of options granted during the six months ended June 30, 2024 and 2023 were $1.45 and $4.43, respectively. The fair values in the six months ended June 30, 2024 and 2023 were estimated using the Black-Scholes option-pricing model based on the following assumptions: Six Months Ended June 30, 2024 2023 Risk-free interest rate 3.77% - 4.59% 2.92% - 4.03% Expected term 6 years 6 years Expected volatility 103.00% - 107.10% 57.77% - 65.00% Expected dividend yield — — Stock-Based Compensation Expense The Company recorded stock-based compensation expense in the following expense categories in its accompanying unaudited interim consolidated statements of operations: Three Months Ended June 30, Six Months Ended June 30, 2024 2023 2024 2023 Research and development $ (44) $ 24 $ 392 $ 34 General and administrative 669 306 1,290 561 $ 625 $ 330 $ 1,682 $ 595

Related-Party Transactions

Related-Party Transactions	6 Months Ended
	Jun. 30, 2024
Related Party Transactions [Abstract]
Related-Party Transactions	Related-Party Transactions The Company has outstanding licensing and scientific research agreements with the University of Pennsylvania (Penn), a significant stockholder as of June 30, 2023. As of December 31, 2023, Penn was no longer a significant stockholder. No expense was recognized for the three months ended June 30, 2023. The Company recognized $0.3 million of research and development expenses for the six months ended June 30, 2023 related to the Penn License Agreement.

Moderna Collaboration and Licen

Moderna Collaboration and License Agreement	6 Months Ended
	Jun. 30, 2024
Revenue from Contract with Customer [Abstract]
Moderna Collaboration and License Agreement	Moderna Collaboration and License Agreement In January 2022, the Company entered into the Moderna License Agreement, which provides for a broad strategic collaboration to discover, develop and commercialize in vivo engineered CAR-M therapeutics for up to twelve oncology programs. Moderna has the right to designate up to twelve research targets as development targets. The first five research targets have been designated and all programs are currently in the discovery phase. Upon Moderna’s election of a development target (and payment of a related development target designation milestone) for commencement of pre-clinical development of a product candidate, the Company will grant Moderna an exclusive worldwide, sublicensable royalty bearing license to develop, manufacture and commercialize the product candidate. Under the terms of the Moderna License Agreement, Moderna made an upfront non-refundable payment of $45.0 million to the Company. Assuming Moderna develops and commercializes 12 products, each directed to a different development target, the Company is eligible to receive up to between $247.0 million and $253.0 million per product in development target designation, development, regulatory and commercial milestone payments. Moderna also will reimburse the Company for all costs incurred by the Company in connection with its research and development activities under the Moderna License Agreement plus a reasonable margin for the respective services performed (with a minimum commitment to reimburse $10.0 million in research and development costs over the first three years from execution of the Moderna License Agreement). The Company is also eligible to receive tiered mid-to-high single digit royalties of net sales of any products that are commercialized under the agreement, which may be, subject to reductions. In addition, Moderna has agreed to cover the cost the Company incurs for certain milestone payments and royalties that the Company owes as a licensor under one of its intellectual property in-license agreements with Penn, which is sublicensed to Moderna under the Moderna License Agreement. Moderna may deduct these royalties in part from any royalties owed to the Company. The Moderna License Agreement terminates on a product-by-product basis upon the latest of expiration of the applicable product patents, expiration of regulatory exclusivity and the tenth anniversary of first commercial sale, unless terminated earlier by the Company or Moderna. At commencement, the Company identified several potential performance obligations within the Moderna License Agreement, including research and development services on research targets, option rights held by Moderna, a non-exclusive royalty-free license to use the Company’s intellectual property to conduct research and development activities and participation on the joint steering committee (JSC). The Company determined that there were 2 performance obligations comprised of (i) research and development services and (ii) option rights. For the research and development services, the stand-alone selling price was determined considering the expected passthrough costs and cost of the research and development services and a reasonable margin for the respective services. The material rights from the option rights were valued based on the estimated discount at which the option is priced and the Company’s estimated probability of the options’ exercise as of the time of the agreement. The transaction price allocated to research and development services is recognized as collaboration revenues as the research and development services are provided to satisfy the underlying obligation related to the research and development target. The transfer of control occurs over this period and, in management’s judgment, is the best measure of progress towards satisfying the performance obligation. The transaction price of $45.0 million allocated to the options rights, which are considered material rights, will be recognized in the period that Moderna elects to exercise or elects to not exercise its option right to license and commercialize the underlying research and development target. In June 2024, the Company received notice from Moderna that Moderna had nominated the first development candidate, an in vivo antigen receptor macrophage targeting Glypican-3 that is designed to treat solid tumor s, including hepatocellular carcinoma . Pursuant to the terms of the Moderna License Agreement, the nomination triggered a $2.0 million milestone payment from Moderna to the Company. As a result, the Company recorded a collaboration receivable and recognized collaboration revenue of $2.0 million. On July 3, 2024, the Company received the $2.0 million payment from Moderna. In addition, the Company reduced its $45.0 million deferred revenue liability associated with the option rights by recognizing $3.8 million in collaboration revenue, which represents a proportional reduction based on the 12 potential early stage targets. The Company included the $45.0 million up-front and nonrefundable payment and $73.9 million of variable consideration for expected research and development services to be performed during the five-year contract term, inclusive of passthrough costs, in the transaction price as of the outset of the arrangement. During the three months ended June 30, 2024 and 2023, the Company recognized $9.2 million and $3.6 million, respectively, of collaboration revenues. During the six months ended June 30, 2024 and 2023, the Company recognized $12.6 million and $6.8 million, respectively, of collaboration revenues. Collaboration revenues for the three and six months ended June 30, 2024 include $3.8 million of deferred option rights revenue recognition and $2.0 million of milestones. The Company recognized $31.6 million and $3.8 million, respectively, of research and development services and option right collaboration revenues since inception of the Moderna License Agreement through June 30, 2024. The following table includes estimated revenue expected to be recognized in the future related to performance obligations that are unsatisfied as of June 30, 2024 (in thousands): Transaction Performance obligations: Research and development $ 42,339 Option rights 41,250 Total performance obligations $ 83,589 Amounts due to the Company for satisfying the revenue recognition criteria or that are contractually due based upon the terms of the collaboration agreements are recorded as accounts receivable in the Company’s unaudited interim consolidated balance sheets. Contract liabilities consist of amounts received prior to satisfying the revenue recognition criteria, which are recorded as deferred revenue in the Company’s unaudited interim consolidated balance sheets. The following table summarizes the changes in deferred revenue (in thousands): Six Months Ended June 30, 2024 2023 Balance at the beginning of the period $ 46,413 $ 47,459 Deferral of revenue 6,090 5,760 Recognition of unearned revenue (10,594) (6,803) Balance at the end of the period $ 41,909 $ 46,416 The current portion of deferred revenue represents advanced payments received from Moderna for costs expected to be incurred by the Company within the next twelve months. The noncurrent portion of deferred revenue represents the unearned portion of the upfront, non-refundable and non-creditable payment allocated to Moderna's option rights of $41.3 million, which is not expected to be recognized within the next 12 months.

Subsequent Events

Subsequent Events	6 Months Ended
	Jun. 30, 2024
Subsequent Events [Abstract]
Subsequent Events	Subsequent Events The Company has evaluated subsequent events from the balance sheet date through August 8, 2024, the issuance date of these unaudited interim consolidated financial statements, and has not identified any additional items that have not previously been mentioned elsewhere requiring disclosure.

Pay vs Performance Disclosure

Pay vs Performance Disclosure - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2024	Jun. 30, 2023	Jun. 30, 2024	Jun. 30, 2023
Pay vs Performance Disclosure
Net loss	$ (11,162)	$ (19,876)	$ (30,140)	$ (44,518)

Insider Trading Arrangements

Insider Trading Arrangements	3 Months Ended
	Jun. 30, 2024
Trading Arrangements, by Individual
Rule 10b5-1 Arrangement Adopted	false
Non-Rule 10b5-1 Arrangement Adopted	false
Rule 10b5-1 Arrangement Terminated	false
Non-Rule 10b5-1 Arrangement Terminated	false

Summary of Significant Accoun_2

Summary of Significant Accounting Policies (Policies)	6 Months Ended
	Jun. 30, 2024
Accounting Policies [Abstract]
Interim Financial Statements	Interim Financial Statements The summary of significant accounting policies is included in the Company’s audited consolidated financial statements and related notes as of and for the year ended December 31, 2023 found in the Annual Report filed on Form 10-K filed with the Securities and Exchange Commission (SEC) on April 1, 2024. The accompanying unaudited interim consolidated financial statements have been prepared in accordance with U.S. generally accepted accounting principles (GAAP). Any references in these notes to applicable guidance is meant to refer to GAAP as found in Accounting Standards Codification (ASC) and Accounting Standards Update (ASU) promulgated by the Financial Accounting Standards Board (FASB). The accompanying unaudited interim consolidated financial statements include the accounts of the Company and its wholly owned subsidiaries. In the opinion of management, the accompanying unaudited interim consolidated financial statements include all normal and recurring adjustments (which consist primarily of accruals, estimates and assumptions that impact the unaudited interim consolidated financial statements) considered necessary to present fairly the Company’s financial position as of June 30, 2024 and its results of operations for the three and six months ended June 30, 2024 and 2023. Operating results for the three and six months ended June 30, 2024 are not necessarily indicative of the results that may be expected for the year ending December 31, 2024. The unaudited interim consolidated financial statements, presented herein, do not contain all of the required disclosures under GAAP for annual financial statements. The accompanying unaudited interim consolidated financial statements should be read in conjunction with the audited consolidated financial statements and related notes as of and for the year ended December 31, 2023 found in the Annual Report filed on Form 10-K filed with the SEC on April 1, 2024.
Use of Estimates	Use of Estimates The preparation of unaudited interim consolidated financial statements in conformity with GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at the date of the unaudited interim consolidated financial statements and the reported amounts of revenues and expenses during the reporting period. Actual results could differ from such estimates. Estimates and assumptions are periodically reviewed, and the effects of revisions are reflected in the unaudited interim consolidated financial statements in the period they are determined to be necessary. Significant areas that require management’s estimates include accrued research and development expenses.
Fair Value of Financial Instruments	Fair Value of Financial Instruments
Fair Value Measurements	Fair Value Measurements The Company utilizes valuation techniques that maximize the use of observable inputs and minimize the use of unobservable inputs to the extent possible. The Company determines fair value based on assumptions that market participants would use in pricing an asset or liability in the principal or most advantageous market. When considering market participant assumptions in fair value measurements, the following fair value hierarchy distinguishes between observable and unobservable inputs, which are categorized in one of the following levels: • Level 1 Inputs: Unadjusted quoted prices in active markets for identical assets or liabilities accessible to the reporting entity at the measurement date. • Level 2 Inputs: Other than quoted prices included in Level 1 inputs that are observable for the asset or liability, either directly or indirectly, for substantially the full term of the asset or liability. • Level 3 Inputs: Unobservable inputs for the asset or liability used to measure fair value to the extent that observable inputs are not available, thereby allowing for situations in which there is little, if any, market activity for the asset or liability at the measurement date. The following fair value hierarchy table presents information about the Company’s assets and liabilities measured at fair value on a recurring basis: (in thousands) Fair value measurement at reporting date using (Level 1) (Level 2) (Level 3) June 30, 2024 Assets: Cash equivalents – money markets accounts $ 37,288 $ — $ — December 31, 2023 Assets: Cash equivalents – money markets accounts $ 62,999 $ — $ — During the six months ended June 30, 2024 and 2023, there were no transfers between Level 1, Level 2 and Level 3.
Concentration of credit risk	Concentration of credit risk Financial instruments that potentially subject the Company to significant concentrations of credit risk consist primarily of cash and cash equivalents. The Company maintains deposits in federally insured financial institutions in excess of federally insured limits. The Company has not experienced any losses in such accounts and believes it is not exposed to significant risk on its cash and cash equivalents.
Segment information	Segment information Operating segments are defined as components of an enterprise about which separate discrete information is available for evaluation by the chief operating decision maker, or decision-making group, in deciding how to allocate resources and in assessing performance. The Company views its operations and manages its business in one segment.
Net loss per share	Net loss per share Basic net loss per share of common stock is computed by dividing net loss by the weighted-average number of shares of common stock outstanding during each period. Diluted net loss per share of common stock includes the effect, if any, from the potential exercise or conversion of securities, such as convertible preferred stock and stock options, which would result in the issuance of incremental shares of common stock. For diluted net loss per share, the weighted-average number of shares of common stock is the same for basic net loss per share due to the fact that when a net loss exists, potentially dilutive securities are not included in the calculation as their impact is anti-dilutive. The following potentially dilutive securities have been excluded from the computation of diluted weighted-average shares of common stock outstanding, as they would be anti-dilutive: June 30, 2024 2023 Stock options 8,685,238 6,655,749
Recently issued accounting pronouncements	Recently issued accounting pronouncements In November 2023, the FASB issued ASU 2023-07, Segment Reporting (Topic 280): Improvements to Reportable Segment Disclosures (ASU 2023-07), which requires disclosure of incremental segment information on an annual and interim basis. This ASU is effective for fiscal years beginning after December 15, 2023, and interim periods within fiscal years beginning after December 15, 2024 on a retrospective basis. The Company is currently evaluating the effect of this pronouncement on its disclosures. In December 2023, the FASB issued ASU 2023-09, Income Taxes (Topic 740): Improvements to Income Tax Disclosures (ASU 2023-09), which expands the disclosures required for income taxes. This ASU is effective for fiscal years beginning after December 15, 2024, with early adoption permitted. The amendment should be applied on a prospective basis while retrospective application is permitted. The Company is currently evaluating the effect of this pronouncement on its disclosures.

Summary of Significant Accoun_3

Summary of Significant Accounting Policies (Tables)	6 Months Ended
	Jun. 30, 2024
Accounting Policies [Abstract]
Schedule of Fair Value Hierarchy of Assets and Liabilities Measured on Recurring Basis	The following fair value hierarchy table presents information about the Company’s assets and liabilities measured at fair value on a recurring basis: (in thousands) Fair value measurement at reporting date using (Level 1) (Level 2) (Level 3) June 30, 2024 Assets: Cash equivalents – money markets accounts $ 37,288 $ — $ — December 31, 2023 Assets: Cash equivalents – money markets accounts $ 62,999 $ — $ —
Schedule of Anti-Dilutive Securities	The following potentially dilutive securities have been excluded from the computation of diluted weighted-average shares of common stock outstanding, as they would be anti-dilutive: June 30, 2024 2023 Stock options 8,685,238 6,655,749

Prepaid Expenses and other as_2

Prepaid Expenses and other assets (Tables)	6 Months Ended
	Jun. 30, 2024
Deferred Costs, Capitalized, Prepaid, and Other Assets Disclosure [Abstract]
Schedule of Prepaid Expenses and Other Assets	Prepaid expenses and other assets consisted of the following (in thousands): June 30, 2024 December 31, 2023 Research and development $ 1,279 $ 278 Novartis credit (Note 6) 4,000 — Collaboration Receivable (Note 10) 2,000 — Deposits 1,548 891 Insurance 725 402 Other 807 1,295 $ 10,359 $ 2,866

Accrued Expenses (Tables)

Accrued Expenses (Tables)	6 Months Ended
	Jun. 30, 2024
Payables and Accruals [Abstract]
Schedule of Accrued Expenses	Accrued expenses consisted of the following (in thousands): June 30, 2024 December 31, 2023 Research and development $ 2,803 $ 3,131 Professional fees 414 1,366 Compensation and related expenses 1,562 3,100 Novartis termination fee (Note 6) 4,409 — Other 53 65 $ 9,241 $ 7,662

Commitments and Contingencies (

Commitments and Contingencies (Tables)	6 Months Ended
	Jun. 30, 2024
Commitments and Contingencies Disclosure [Abstract]
Schedule of Lease Costs	The elements of the lease costs were as follows (in thousands): Six Months Ended June 30, 2024 2023 Operating lease cost $ 3,154 $ 2,875 Finance lease cost: Amortization of lease assets 1,008 593 Interest on lease liabilities 159 88 Total finance lease cost 1,167 681 Variable lease cost 672 653 Total lease cost $ 4,993 $ 4,209
Schedule of Lease Term and Discount Rate Information	Lease term and discount rate information related to leases was as follows: June 30, 2024 2023 Weighted-average remaining lease term (in years) Operating leases 2.5 2.2 Finance leases 1.4 1.7 Weighted-average discount rate Operating leases 9.8 % 9.6 % Finance leases 9.0 % 9.0 %
Schedule of Supplemental Cash Flow Information	Supplemental cash flow information was as follows (in thousands): Six Months Ended 2024 2023 Cash paid for amounts included in the measurement of lease liabilities: Operating cash used in operating leases $ 3,203 $ 2,584 Operating cash used in finance leases $ 159 $ 88 Financing cash used in finance leases $ 906 $ 213
Schedule of Future Maturities of Lease Liabilities	Future maturities of lease liabilities were as follows as of June 30, 2024 (in thousands): Operating Finance Fiscal year ending: 2024 (remaining six months) $ 1,177 $ 631 2025 219 1,261 2026 226 20 2027 233 — 2028 240 — Thereafter 184 — Total future minimum payments 2,279 1,912 Less imputed interest (305) (127) Present value of lease liabilities $ 1,974 $ 1,785

Stock-based Compensation (Table

Stock-based Compensation (Tables)	6 Months Ended
	Jun. 30, 2024
Share-Based Payment Arrangement [Abstract]
Schedule of Stock Option Activity	The following table summarizes stock option activity for the six months ended June 30, 2024: Options Weighted Weighted Aggregate Outstanding as of December 31, 2023 6,023,370 $ 3.94 Exercised (3,810) 0.99 $ 4 Granted 3,674,365 1.77 Forfeited (1,008,687) 4.70 Outstanding as of June 30, 2024 8,685,238 $ 2.93 8.14 $ 2,018 Exercisable as of June 30, 2024 3,487,670 $ 2.19 6.40 $ 1,517
Schedule of Estimated Using The Black-Scholes Option-Pricing Model	The fair values in the six months ended June 30, 2024 and 2023 were estimated using the Black-Scholes option-pricing model based on the following assumptions: Six Months Ended June 30, 2024 2023 Risk-free interest rate 3.77% - 4.59% 2.92% - 4.03% Expected term 6 years 6 years Expected volatility 103.00% - 107.10% 57.77% - 65.00% Expected dividend yield — —
Schedule of Stock-based Compensation Expense	The Company recorded stock-based compensation expense in the following expense categories in its accompanying unaudited interim consolidated statements of operations: Three Months Ended June 30, Six Months Ended June 30, 2024 2023 2024 2023 Research and development $ (44) $ 24 $ 392 $ 34 General and administrative 669 306 1,290 561 $ 625 $ 330 $ 1,682 $ 595

Moderna Collaboration and Lic_2

Moderna Collaboration and License Agreement (Tables)	6 Months Ended
	Jun. 30, 2024
Revenue from Contract with Customer [Abstract]
Schedule of Estimated Revenue Expected to be Recognized in The Future Related to Performance Obligations	The following table includes estimated revenue expected to be recognized in the future related to performance obligations that are unsatisfied as of June 30, 2024 (in thousands): Transaction Performance obligations: Research and development $ 42,339 Option rights 41,250 Total performance obligations $ 83,589
Schedule of Changes in Deferred Revenue	The following table summarizes the changes in deferred revenue (in thousands): Six Months Ended June 30, 2024 2023 Balance at the beginning of the period $ 46,413 $ 47,459 Deferral of revenue 6,090 5,760 Recognition of unearned revenue (10,594) (6,803) Balance at the end of the period $ 41,909 $ 46,416

Development-Stage Risks and L_2

Development-Stage Risks and Liquidity (Details) - USD ($) $ in Thousands	Jun. 30, 2024	Dec. 31, 2023
Unusual Risk or Uncertainty [Line Items]
Accumulated deficit	$ 275,242	$ 245,102
Cash, cash equivalents and marketable securities	40,400
Moderna | Moderna License Agreement
Unusual Risk or Uncertainty [Line Items]
Milestone payment	$ 2,000

Summary of Significant Accoun_4

Summary of Significant Accounting Policies - Schedule of Fair Value Hierarchy of Assets and Liabilities Measured on Recurring Basis (Details) - Recurring - USD ($) $ in Thousands	Jun. 30, 2024	Dec. 31, 2023
Level 1
Assets:
Cash equivalents – money markets accounts	$ 37,288	$ 62,999
Level 2
Assets:
Cash equivalents – money markets accounts	0	0
Level 3
Assets:
Cash equivalents – money markets accounts	$ 0	$ 0

Summary of Significant Accoun_5

Summary of Significant Accounting Policies - Narrative (Details)	6 Months Ended
	Jun. 30, 2024 segment
Accounting Policies [Abstract]
Number of operating segments	1

Summary of Significant Accoun_6

Summary of Significant Accounting Policies - Schedule of Anti-Dilutive Securities (Details) - shares	6 Months Ended
	Jun. 30, 2024	Jun. 30, 2023
Stock options
Net loss per share
Anti-dilutive securities (in shares)	8,685,238	6,655,749

Prepaid Expenses and other as_3

Prepaid Expenses and other assets (Details) - USD ($) $ in Thousands	Jun. 30, 2024	Dec. 31, 2023
Deferred Costs, Capitalized, Prepaid, and Other Assets Disclosure [Abstract]
Research and development	$ 1,279	$ 278
Novartis credit	4,000	0
Collaboration Receivable	2,000	0
Deposits	1,548	891
Insurance	725	402
Other	807	1,295
Prepaid expenses and other assets	$ 10,359	$ 2,866

Accrued Expenses (Details)

Accrued Expenses (Details) - USD ($) $ in Thousands	Jun. 30, 2024	Dec. 31, 2023
Payables and Accruals [Abstract]
Research and development	$ 2,803	$ 3,131
Professional fees	414	1,366
Compensation and related expenses	1,562	3,100
Novartis termination fee	4,409	0
Other	53	65
Total accrued expenses	$ 9,241	$ 7,662

Commitments and Contingencies -

Commitments and Contingencies - Narratives (Details) - USD ($) $ in Thousands		1 Months Ended
	Jun. 26, 2024	Mar. 31, 2023	Jun. 30, 2024
Commitments and Contingencies
Financing liability			$ 1,785
Laboratory equipment
Commitments and Contingencies
Financing liability			2,000
Novartis Agreement
Commitments and Contingencies
Agreement term		5 years
Renewal term		1 year
Amount payable per calendar year for reserved capacity		$ 1,000
Termination fee payable		$ 4,000	4,000
Contract termination fee	$ 4,000
Prepaid asset resulting from agreement termination			$ 4,000

Commitments and Contingencies_2

Commitments and Contingencies - Schedule of Lease Costs (Details) - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2024	Jun. 30, 2023
Commitments and Contingencies Disclosure [Abstract]
Operating lease cost	$ 3,154	$ 2,875
Finance lease cost:
Amortization of lease assets	1,008	593
Interest on lease liabilities	159	88
Total finance lease cost	1,167	681
Variable lease cost	672	653
Total lease cost	$ 4,993	$ 4,209

Commitments and Contingencies_3

Commitments and Contingencies - Schedule of Lease Term and Discount Rate Information (Details)	Jun. 30, 2024	Jun. 30, 2023
Weighted-average remaining lease term (in years)
Operating leases	2 years 6 months	2 years 2 months 12 days
Finance leases	1 year 4 months 24 days	1 year 8 months 12 days
Weighted-average discount rate
Operating leases	9.80%	9.60%
Finance leases	9%	9%

Commitments and Contingencies_4

Commitments and Contingencies - Schedule of Supplemental Cash Flow Information (Details) - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2024	Jun. 30, 2023
Cash paid for amounts included in the measurement of lease liabilities:
Operating cash used in operating leases	$ 3,203	$ 2,584
Operating cash used in finance leases	159	88
Financing cash used in finance leases	$ 906	$ 213

Commitments and Contingencies_5

Commitments and Contingencies - Schedule of Future Maturities of Lease Liabilities (Details) $ in Thousands	Jun. 30, 2024 USD ($)
Operating Leases
2024 (remaining six months)	$ 1,177
2025	219
2026	226
2027	233
2028	240
Thereafter	184
Total future minimum payments	2,279
Less imputed interest	(305)
Present value of lease liabilities	1,974
Finance Leases
2024 (remaining six months)	631
2025	1,261
2026	20
Total future minimum payments	1,912
Less imputed interest	(127)
Present value of lease liabilities	$ 1,785

Stockholders' Equity (Details)

Stockholders' Equity (Details) - At-the-Market - USD ($)	6 Months Ended
	Jun. 30, 2024	May 12, 2023
Subsidiary or Equity Method Investee [Line Items]
Sale of stock, maximum aggregate offering price		$ 100,000,000
Sales of stock (in shares)	931,250
Sale of stock, consideration received on transaction	$ 2,300,000

Stock-based Compensation - Narr

Stock-based Compensation - Narratives (Details) shares in Millions	6 Months Ended
	Jun. 30, 2024 shares
Two Thousand Seventeen Stock Incentive Plan | Stock options
Stock-based Compensation
Terms	10 years
Vesting period	4 years
Two Thousand Fourteen Stock Incentive Plan
Stock-based Compensation
Terms	10 years
Vesting period	4 years
Shares available for issuance	3.8
Two Thousand Fourteen Employee Stock Purchase Plan
Stock-based Compensation
Shares available for issuance	0.2

Stock-based Compensation - Sche

Stock-based Compensation - Schedule of Stock Option Activity (Details) $ / shares in Units, $ in Thousands	6 Months Ended
	Jun. 30, 2024 USD ($) $ / shares shares	Jun. 30, 2023 $ / shares
Options
Outstanding as of December 31, 2023 (in shares) | shares	6,023,370
Exercised (in shares) | shares	(3,810)
Granted (in shares) | shares	3,674,365
Forfeited (in shares) | shares	(1,008,687)
Outstanding as of June 30, 2024 (in shares) | shares	8,685,238
Exercisable as of June 30, 2024 (in shares) | shares	3,487,670
Weighted average exercise price
Outstanding as of December 31, 2023 (in USD per share)	$ 3.94
Exercised (in USD per share)	0.99
Granted (in USD per share)	1.77
Forfeited (in USD per share)	4.70
Outstanding as of June 30, 2024 (in USD per share)	2.93
Exercisable as of June 30, 2024 (in USD per share)	2.19
Share based compensation arrangement by share based payment award options grants in period weighted average grant date fair value (in USD per share)	$ 1.45	$ 4.43
Weighted average remaining contractual term (years)
Outstanding as of June 30, 2024	8 years 1 month 20 days
Exercisable as of June 30, 2024	6 years 4 months 24 days
Aggregate Intrinsic Value
Exercised | $	$ 4
Outstanding as of June 30, 2024 | $	2,018
Exercisable as of June 30, 2024 | $	$ 1,517

Stock-based Compensation - Sc_2

Stock-based Compensation - Schedule of Estimated Using The Black-Scholes Option-Pricing Model (Details) - Stock options	6 Months Ended
	Jun. 30, 2024	Jun. 30, 2023
Stock-based Compensation
Expected term	6 years	6 years
Expected dividend yield	0%	0%
Minimum
Stock-based Compensation
Risk-free interest rate	3.77%	2.92%
Expected volatility	103%	57.77%
Maximum
Stock-based Compensation
Risk-free interest rate	4.59%	4.03%
Expected volatility	107.10%	65%

Stock-based Compensation - Sc_3

Stock-based Compensation - Schedule of Stock-based Compensation Expense (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2024	Jun. 30, 2023	Jun. 30, 2024	Jun. 30, 2023
Stock-based Compensation
Stock-based compensation expense	$ 625	$ 330	$ 1,682	$ 595
Stock-based options forfeited (in shares)			1,008,687
Future compensation cost for awards not vested	$ 11,800		$ 11,800
Weighted-average period compensation cost of unvested awards to be expensed			2 years 10 months 24 days
Revised Operating Plan
Stock-based Compensation
Stock-based options forfeited (in shares)	869,800
Sesen Bio, Inc.
Stock-based Compensation
Stock-based compensation expense				200
Research and development
Stock-based Compensation
Stock-based compensation expense	$ (44)	24	$ 392	34
General and administrative
Stock-based Compensation
Stock-based compensation expense	$ 669	$ 306	$ 1,290	$ 561

Related-Party Transactions (Det

Related-Party Transactions (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2024	Jun. 30, 2023	Jun. 30, 2024	Jun. 30, 2023
Related-Party Transactions
Research and development	$ 15,307	$ 18,518	$ 32,769	$ 35,159
Penn
Related-Party Transactions
Research and development				$ 300

Moderna Collaboration and Lic_3

Moderna Collaboration and License Agreement - Narratives (Details) $ in Thousands		1 Months Ended		3 Months Ended		6 Months Ended		30 Months Ended
	Jul. 03, 2024 USD ($)	Jun. 30, 2024 USD ($)	Jan. 31, 2022 USD ($) product target	Jun. 30, 2024 USD ($)	Jun. 30, 2023 USD ($)	Jun. 30, 2024 USD ($) obligation target	Jun. 30, 2023 USD ($)	Jun. 30, 2024 USD ($)	Dec. 31, 2023 USD ($)	Dec. 31, 2022 USD ($)
Moderna Collaboration and License Agreement
Collaboration revenues				$ 9,200	$ 3,600	$ 12,600	$ 6,800
Deferred revenue liability		$ 41,909		41,909	46,416	41,909	46,416	$ 41,909	$ 46,413	$ 47,459
Collaboration revenues				9,197	$ 3,560	12,594	$ 6,803
Option Right Collaboration Revenues
Moderna Collaboration and License Agreement
Collaboration revenues				3,800		3,800
Milestones
Moderna Collaboration and License Agreement
Collaboration revenues				2,000		$ 2,000
Collaboration and License Agreement
Moderna Collaboration and License Agreement
Number of potential research target designations | target						12
Collaboration and License Agreement | Research and Development Services
Moderna Collaboration and License Agreement
Variable consideration						$ 73,900
Term of contract						5 years
Noncurrent portion of deferred revenue		41,300		41,300		$ 41,300		41,300
Collaboration and License Agreement | Moderna
Moderna Collaboration and License Agreement
Maximum of research targets | target			12
Number of research targets, designate as development targets | target			12
Number of research targets designated | target			5
Collaboration and License Agreement | Moderna | Research and Development Services
Moderna Collaboration and License Agreement
Upfront non-refundable payment received			$ 45,000			$ 45,000
Number of potential products to develop and commercialize | product			12
Minimum commitment to reimburse research and development costs			$ 10,000
Period of reimbursement of research and development costs			3 years
Number of performance obligations | obligation						2
Collaboration and License Agreement | Moderna | Minimum | Research and Development Services
Moderna Collaboration and License Agreement
Amount receivable per product			$ 247,000
Collaboration and License Agreement | Moderna | Maximum | Research and Development Services
Moderna Collaboration and License Agreement
Amount receivable per product			$ 253,000
Moderna License Agreement | Research and Development Services
Moderna Collaboration and License Agreement
Collaboration revenues								31,600
Moderna License Agreement | Option Right Collaboration Revenues
Moderna Collaboration and License Agreement
Collaboration revenues								3,800
Moderna License Agreement | Moderna
Moderna Collaboration and License Agreement
Milestone payment		2,000		2,000		$ 2,000		2,000
Collaboration revenues		2,000
Deferred revenue liability		$ 45,000		$ 45,000		45,000		$ 45,000
Decrease in contract with customer, liability						$ 3,800
Moderna License Agreement | Moderna | Subsequent Event
Moderna Collaboration and License Agreement
Proceeds related to collaboration revenue	$ 2,000

Moderna Collaboration and Lic_4

Moderna Collaboration and License Agreement - Schedule of Estimated Revenue Expected to be Recognized in The Future Related to Performance Obligations (Details) $ in Thousands	Jun. 30, 2024 USD ($)
Performance obligations:
Research and development	$ 42,339
Option rights	41,250
Total performance obligations	$ 83,589

Moderna Collaboration and Lic_5

Moderna Collaboration and License Agreement - Schedule of Changes in Deferred Revenue (Details) - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2024	Jun. 30, 2023
Movement in Deferred Revenue [Roll Forward]
Balance at the beginning of the period	$ 46,413	$ 47,459
Deferral of revenue	6,090	5,760
Recognition of unearned revenue	(10,594)	(6,803)
Balance at the ending of the period	$ 41,909	$ 46,416